You don't appear to have any idea about the OM-D's focussing speed and capability.

I know it cannot do this

You know how?

You assume, perhaps.

I've heard regularly from various m4/3s haters that m4/3s can't focus adequately for sports, action, etc. Yet, when various members of the forum go and try these things, they don't seem to have any such issue.

Let's not forget

"Olympus claims that the E-M5 offers the fastest autofocus in the world when paired with the 12-50mm F3.5-6.3 lens (at least for for single focus acquisition), and we have little reason to doubt that. The focus is near-instant in good light and only drops off in very low light." - DPReview.